40.5 kV SF6充气式开关柜三维电场分析

建立了40.5 kV、2 000 ASF6充气式开关柜的三维电场分析的有限元模型。针对产品实际结构的复杂性,应用网格划分控制工具的参数设置和疏密网格等分网方式对模型进行网格划分,按照实体模型的边界线或边界面的曲率排布设置了中间节点、边中节点,使有限元模型与实体模型的边界更吻合。同时采用局部细化、重新分网等方法提高网格的质量。考虑大型稀疏方程组迭代收敛以及收敛速度快慢的问题,通过几种求解方法的比较,选用不完全乔类斯基共轭梯度(incomplete Cholesky-conjugate gradient,ICCG)算法进行大型有限元方程组的求解。该文通过计算分析获得了充气柜2个气室(隔离开关室和断路器室)的电位和电场强度的分布规律,以及相关结构参数对电场分布的影响,从而对SF6充气柜(cubicle gas-insulated metal-enclosed switchgear,C-GIS)的绝缘结构设计提供理论参考。     

Generalized probability density function and applications to the experimental data in electrical circuits and systems

The mathematical sciences, and particularly probabilistic and statistical methods, are key to understanding the dependencies of the systems. The purpose of this paper is to encourage a wider recognition by engineers of a new generalized principle which in its mathematical form is a powerful instrument for the solution of practical problems. Generalized probability density function was introduced to permit analysis without pre-knowledge of the source of the data. The fundamental principles are extended to apply the most related engineering applications without the need to know the type of source generating the data. The generalized model presented eliminates preliminary work in engineering problems. The proposed model introduces an exponential density function to produce a direct solution to randomly varying data. The exponential density function is fully compatible with applications containing randomly distributed data. The success of the generalized model presented is due to the calculated parameters in the exponential density function. The method is applied to various problems chosen from the field of engineering with great success.     

三峡电站不完全裂相横差保护的灵敏度分析

采用“多回路分析法”对三峡电站1号和2号发电机所有可以发生的同槽和端部交叉故障进行了计算,在此基础上计算了上述每一种故障条件下传统裂相横差保护和不完全裂相差保护的灵敏度,并对两种保护方案的灵敏动作数,可能动作数和不能动作数进行了统计,然后进一步分析了不能协作故障的性质。依据计算和统计结果,分析了两种保护方案对于不同结构发电机的灵敏度的差异。     

自耦联络变压器区域化保护配置研讨

通过对常见的几种方向性保护性保护配置方案的分析，指出以往自耦联络变压器后备保护方案中方向性保护配置存在的问题。为解决这些问题，首次提出区域化保护这一概念，并给出自耦联络变压器的区域化电量保护方案。使用该保护方案，可简化保护整定配合，提高后备保护动作速度，解决第三绕组的后备保护问题，同时易于实现保护装置的模块化。     

从图纸会审与施工组织设计的相依性探究投资项目价值工程的意义

图纸会审是项目技术管理的重要内容,设计图纸是进行工程建造的主要依据;会审好图纸,明确建设项目的特点和经济及技术指标,是项目参与人员确保项目工程质量、控制投资、实现项目工期的前提。而施工组织设计是项目施工过程前期工作的重要一环,其编制不但关系到施工单位自身的成本,还关系到项目业主的投资效益。实践中,从以上两个阶段的相依性来开展价值工程的探究,最大程度地节约成本、提高投资效益,是非常有意义的。     

当联合概率密度未知时随机结构可靠性分析的随机有限元法

建立了在基本随机变量的联合概率密度未知的情况下随机结构可靠性分析的随机有限元法,阐述了受有随机载荷的多随机参数结构的失败概率的计算方法,应用已知的基本随机变量的前两阶矩和边缘概率分布函数对随机结构的可靠性进行了分析。     

蟠龙水电站工程可研阶段施工组织设计研究

对蟠龙水电站可研设计阶段的施工组织设计关键技术问题进行了深入论证分析,提出了合理的施工导流方式、导流建筑物布置方案。工程采用分期围堰、明渠导流方案,分区布置5套混凝土拌和站和砂石系统。施工组织设计中,还对主体工程施工、施工工厂设施布置、总布置、交通运输、施工总进度等进行优化设计研究。拟定施工总工期为32个月,首台机组发电工期为27个月。     

ANALYSIS OF SOLUBLE CHEMICAL TRANSFER BY RUNOFF WATER IN FIELD

In order to determine the main factors influencing soluble chemical transfer and corresponding techniques for reducing fertilizer loss caused by runoff in irrigated fields, a physically based two-layer model was developed with incomplete mixing theory. Different forms of incomplete mixing parameters were introduced in the model, which was successfully verified with previous published experimental data. According to comparison, the chemicals loss of fertilizer is very sensitive to the runoff-related parameter while it is not sensitive to the infiltration-related parameter. The calculated results show that the chemicals in infiltration water play an important role in the early time of rainfall even with saturated soil, and it is mainly in the runoff flow in the late rainfall. Therefore, prevention of shallow subsurface drainage in the early rainfall is an effective way to reduce fertilizer loss, and the coverage on soil surface is another effective way.     

现代皮革服装装饰设计方法探讨

从改变皮革服装面料的触觉和视觉肌理两个方面入手，阐述了现代皮革服装的诸种装饰设计方法。     

出山店水库表孔低水头大单宽流量消能方式研究

由于出山店水库下游河床水位低且水深变幅较大,能量较为集中,对下游冲刷严重,传统消能方式很难满足工程需求。本文结合出山店混凝土坝下消能防冲实验研究成果,对宽尾墩的水流特点、掺气特征、消能效果等进行了探讨,再通过数值模拟得出的水面线计算成果与实验结果吻合良好。最后,经过模型试验、数值模拟的结果进行比选,得出溢流表孔采用底流消能同时联合T型墩、非完全宽尾墩等辅助消能方式的消能率有所提高,消能效果提升明显。本研究可为类似的低水头、大单宽流量、低佛劳德数水库消能设计与试验研究提供参考。